The STILT calculator is available at https://stilt.icos-cp.eu/worker/.
You will have to log in through ATMO-ACCESS to use it and will be automatically redirected to their login page.
Step 1: Select the station location
a) Already defined stations can be selected from the drop-down list or by locating them on the map.
Alternatively, you can type in the name in 'station id' and press 'load data' to load the predefined coordinates.
b) If you want to start a run for an already existing location but a new measurement height, first select the 'Site id' of the existing site and load the predefined coordinates. Next change the altitude in the 'Site id' and in the 'Altitude' box to the new measurement height.
c) For a new station location enter latitude, longitude and measurement height above ground in the respective boxes. Another option to enter latitude and longitude is to click on the map.
Define a new (unique) 'Site id' following the scheme of a 3-letter code, extended by 3 digits for the measurement height in case of several heights.
Note that the station should not be located very close to the boundaries of the model domain (34°N - 72°N, 14°W-34°E).
Please provide a 'Site name' for your new location, could be the name of the measurement station or of a nearby town.
Select the country in which the new site is located from the drop-down list.
For mountain stations, see the specific instructions at the end of this page.
Step 2: Select the time range
Enter start and end date in the respective boxes or use the calendar tool. Valid dates are highlighted in the calendar tool, starting 2006-03-01.
Footprints and concentrations will be calculated for 3-hourly intervals (00:00, 03:00, 06:00, 09:00, 12:00, 15:00, 18:00, and 21:00 UTC) for each day in the time range.
Note that a calculation for one single day may take up to 24 minutes on a single CPU (or less if all CPUs are available for the job) and waiting time can occur in case of several concurrent calculations.
Step 3: Submit your job
Submit your job by clicking 'Submit STILT job'.
Step 4: Check the progress of your computation
You can check the progress of the computation on the dashboard by clicking 'Show details'. Your job should show up on the list of running computations, identifiable by the email address you used to log in. Note that you can still delete your submitted job during runtime.
The progress of the computations is indicated by the number of finished time steps.
The overall status of the compute server is shown by the number of busy CPUs in relation to the total number of available CPUs, listed at the top of the dashboard.
Step 5: View the results
As soon as the calculations are finished, your job will be moved to the 'Finished computations' list and a 'View results' button will lead you to the visualization on a job-specific web page. Find more instructions regarding the visualization here.
Your new results are now also available on the list of stations in the STILT viewer.
Note that the job list will be updated regularly and your finished jobs will disappear from the list. At this stage, your results are already available in the list of station in the STILT viewer.
In case of problems, do not hesitate to contact us at footprint (at) icos-cp.eu
Specific instructions
- High mountain stations are often difficult to represent in atmospheric transport model simulations. Therefore, they require a special choice of the 'altitude' parameter in the computations.
In the model simulations, the 'altitude' (= measurement height) for a mountain station does not simply correspond to height above ground level, as it would be the case for a flatland site. This would result in an underestimation of the vertical position in the troposphere, because mountains are not fully resolved be the orography used in the model. On the other hand, placing the station in the simulations at a higher 'altitude' to offset this underestimation and align with the actual measurement height above sea level would lead to an exaggerated measurement height above ground. This, in turn, would underestimate the interaction between surface fluxes and atmospheric tracer concentration. Currently, we use an expert estimate based on some case studies. So please do not hesitate to contact us for help at footprint (at) icos-cp.eu to find an appropriate choice of the 'altitude' parameter for your mountain site. - Check if computations for a station close by your selected site already exist. With our current model version, simulation results will not be significantly different for stations at less than 10 km distance. Calculations for several sampling heights at tall towers are of course possible.